1. Field of the Invention
The present invention relates to a method of forming an etch barrier in the reactive ion etching of an aromatic polyamic acid/polyimide.
2. Description of the Prior Art
IBM Technical Disclosure Bulletin Vol. 25, No. 2, July, 1982, pages 523 and 524 discloses a method of replacing the dianiline group in a cured polyimide with a disiloxane, disilarylene or disilalkylene group. The cured polyimide is reacted with a diamino disiloxane or diamino disilarylene or a disilalkylene in a solvent such as N-methyl-pyrrolidone.
In a paper presented at the First Technical Conference on Polyimides in November of 1982 entitled "Polyimide Siloxane for Electronic Application" by Davis et al. the use of silicone containing polyimides is disclosed which can be spin-coated for microelectronic applications. Patterning of the polyimide siloxane is accomplished by wet chemical or dry etching techniques. It is further disclosed that in pure oxygen the rate of polyimide siloxane etching is considerably less that that of other polymer films which were tested and a residue after etching remains.
In a paper at the same conference entitled "Thermal Studies of Compositional Variations of Some Novel Silicon Polyimides" Chowdhury et al., polysilicone imides are disclosed resulting from the modification of aromatic polyimides by specially equilibrated silicone blocks. The products are stated to exhibit good adhesion and electrical properties.
In a paper at the same conference entitled "Modified Polyimides by Silicon Block Incorporation" by Berger et al., copolymerization of a variety of dianhydrides with molar quantities of organic diamines and/or aminofunctional di/or polysiloxanes is disclosed. The products are stated to exhibit excellent adhesion, weatherability, good thermal cycling properties, controlled elongation, high solubility, etc.
U.S. Pat. No. 3,338,859 Green discloses silicone polyimides which are stated to have unique electrical properties as well as excellent stability.
U.S. Pat. No. 3,392,144 Holub discloses polyamide compositions prepared by reacting a phthaloyl compound with an organosilicon diamine or with a mixture of the latter and an organic diamine free of silicon. The products obtained by heat treatment of the aforesaid reaction products are stated to be useful as heat-resistant protective and insulating members.
U.S. Pat. No. 4,377,437 Taylor et al. discloses implanting ions into a material to chemically incorporate the same therein and render the same non-etchable to an oxygen plasma.